There are a few options and I would love to help because, I too, wear orthotics.
In this situation, I would consult a pediatrist to see if the last or the contour of the innersole coexists with your orthotics and your foot shape. If all seems normal there, a good thing to try would be replacing the innersole and have your own inserted so that will conform to your feet in a way that your more used to.
Also, with different lasts and builds, there is a chance your sizing may be slightly off with that particular shoe. There is really no "exact" solution it seems b/c everyone is different. Also, if they were brand new, could take a few rounds for the shoe to take its true form to your foot!
I wish you all the best and all the luck with your new purchase. And welcome to the Community, keep posting!